$z=12.1+29i$ What is the real part of $z$ ?
Background Complex numbers are numbers of the form $z={a}+{b}i$, where $i$ is the imaginary unit and ${a}$ and ${b}$ are real numbers. [What is the imaginary unit?] The real part of $z$ is denoted by $\text{Re}(z)={a}$. The imaginary part of $z$ is denoted by $\text{Im}(z)={b}.$ Finding the Real and Imaginary Parts of $z$ In this case, $z={12.1}+{29}i$ is of the form ${a}+{b}i$, where ${a}={12.1}$ and ${b}={29}$. Therefore: $\text{Re}(z)={a}={12.1}$. $\text{Im}(z)={b}={29}$. Summary The real part of $z$ is ${12.1}$. The imaginary part of $z$ is ${29}$.